Karl hits the Yucatan; two simultaneous Cat 4s in the Atlantic for 2nd time in history

The Atlantic hurricane season of 2010 kicked into high gear this morning, with the landfall of Tropical Storm Karl in Mexico, and the simultaneous presence of two Category 4 hurricanes in the Atlantic, Igor and Julia. Tropical Storm Karl's formation yesterday marked the fifth earliest date that an eleventh named storm of the season has formed. The only years more active this early in the season were 2005, 1995, 1936 and 1933. This morning's unexpected intensification of Hurricane Julia into a Category 4 storm with 135 mph winds has set a new record--Julia is now the strongest hurricane on record so far east. When one considers that earlier this year, Hurricane Earl became the fourth strongest hurricane so far north, it appears that this year's record SSTs have significantly expanded the area over which major hurricanes can exist over the Atlantic. This morning is just the second time in recorded history that two simultaneous Category 4 or stronger storms have occurred in the Atlantic. The only other occurrence was on 06 UTC September 16, 1926, when the Great Miami Hurricane and Hurricane Four were both Category 4 storms for a six-hour period. The were also two years, 1999 and 1958, when we missed having two simultaneous Category 4 hurricanes by six hours. Julia's ascension to Category 4 status makes it the 4th Category 4 storm of the year. Only two other seasons have had as many as five Category 4 or stronger storms (2005 and 1999), so 2010 ranks in 3rd place in this statistic. This year is also the earliest a fourth Category 4 or stronger storm has formed (though the fourth Category 4 of 1999, Hurricane Gert, formed just 3 hours later on today's date in 1999.) We've also had four Cat 4+ storms in just twenty days, which beats the previous record for shortest time span for four Cat 4+ storms to appear. The previous record was 1999, 24 days (thanks to Phil Klozbach of CSU for this stat.)

Figure 1. A rare double feature: two simultaneous Category 4 hurricanes in the Atlantic, for only the second time in recorded history.

KarlTropical Storm Karl made landfall as a strong tropical storm with 65 mph winds and a central pressure of 991 mb at 8:45am EDT this morning on Mexico's Yucatan Peninsula, just north of the Belize border. Karl took advantage of nearly ideal conditions for intensification, and in just fifteen hours intensified from a tropical disturbance to a strong tropical storm with 65 mph winds. Had Karl managed to get its act together just one day earlier, it could have been a major hurricane at landfall this morning. Fortunately, Karl has a relatively small area of strong winds--tropical storm force winds extend out just 45 miles from the center of the storm, and wind damage is not the main concern. Heavy rains are the main concern, and Belize radar shows heavy rain bands from Karl spreading ashore over northern Belize near the border with Mexico. Cancun radar shows that heavy rains are relatively limited, though, near the tourist havens of Cancun and Cozumel.

Forecast for KarlKarl will traverse the Yucatan Peninsula today and emerge into the Gulf of Mexico's Bay of Campeche Thursday morning as a much weakened tropical storm, with perhaps 40 - 45 mph top winds. Once in the Gulf, conditions for intensification are ideal, with wind shear is expected to be low, 5 - 10 knots, SSTs will be warm, 29°C - 30°C, and the atmosphere very moist. These conditions, combined with the topography of the surrounding coast which tends to enhance counter-clockwise flow, should allow Karl to intensify into a strong tropical storm or a Category 1 hurricane before making landfall between Tampico and Vercruz, Mexico on Saturday morning. However, since Karl is a small storm, it is possible that passage over the Yucatan will disrupt the storm enough so that it will be much weaker. The ridge of high pressure steering Karl westwards is quite strong, and it is very unlikely that the storm will turn northwest and hit Texas. NHC is giving Brownsville, Texas, an 10% chance of receiving tropical storm force winds of 39+ mph.

IgorHurricane Igor put on a burst of intensification last night to put it at its strongest yet, a top-end Category 4 hurricane with 155 mph winds. Igor has weakened slightly this morning, but remains a formidable presence in the Central Atlantic with its 145 mph winds. Igor continues to show the classic appearance of a major hurricane on satellite imagery, with a well-formed eye, symmetrical cloud pattern, plenty of low-level spiral bands, and solid upper-level outflow on all sides.

Intensity forecast for IgorWind shear is low, 5 - 10 knots, and is expected to remain low for the next 2 - 3 days. Waters are warm, 29°C, and will remain 29°C for the next 2 - 3 days. Igor is well armored against any intrusions of dry air for at least the next three days. These conditions should allow Igor to remain at major hurricane status for the next three days. The hurricane will probably undergo one of the usual eyewall replacement cycles intense hurricanes commonly have, where the eyewall collapses and a new eyewall forms from an outer spiral band. This will weaken the hurricane by 10 - 20 mph when it occurs, and may be responsible for the 10 mph weakening Igor experienced early this morning. Igor may regain its lost intensity over the next 36 hours. By Saturday morning, 36 hours before the core of Igor is expected to pass Bermuda's latitude, the trough of low pressure steering Igor northwestwards should bring moderate wind shear of 10 - 20 knots to the storm, weakening it. The SHIPS models predicts shear will rise to the high range, 20 - 30 knots, during the final 24 hours of the storm's approach to Bermuda. Igor will also be tracking over cooler 28°C waters during this period, and substantial weakening by perhaps 20 - 30 mph can be expected. Igor will still probably be at least a Category 2 hurricane on its closest pass by Bermuda on Sunday. NHC is giving Bermuda a 13% chance of experiencing hurricane force winds from Igor, but this probability is likely too low. The Bermuda Weather Service is calling for Category 1 or 2 hurricane conditions for the island on Sunday, with 20 - 25 foot waves in the offshore waters.

Track forecast for IgorThe track forecast for Igor remains unchanged. Igor has made its long-anticipated turn to the west-northwest, in response to the steering influence of a broad trough of low pressure moving across the Western Atlantic. This trough will steer Igor several hundred miles to the northeast of the Lesser Antilles, and high waves should be the only impact of Igor on the islands. Igor appears likely to be a threat to Bermuda, and that island can expect tropical storm force winds as early as Saturday. Igor will be moving at about 12 - 15 mph as it approaches Bermuda. Tropical storm force winds of 39+ mph will probably extend out about 250 miles to the north of Igor on Saturday, so Bermuda can expect 18 hours of tropical storm force winds before the core of Igor makes its closest pass. In all, Bermuda is likely to experience a very long pounding of 24 - 36 hours with winds in excess of tropical storm force.

The models have been in substantial agreement over multiple runs that Igor will miss the U.S. East Coast, and the danger to the U.S. will probably only come in the form of high waves. Large swells from Igor have arrived in the Northern Lesser Antilles Islands, and will spread westwards over the next few days, reaching the U.S. East Coast on Friday. By Saturday, much of the East Coast from northern Florida to Cape Cod Massachusetts can expect waves of 3 - 4 meters (10 - 13 feet), causing dangerous rip currents and significant beach erosion. These waves will continue through Sunday then gradually die down. The latest NOAA marine forecast for Cape Hatteras, North Carolina calls for 8 - 10 foot waves on Saturday, and 9 - 12 foot waves on Sunday.

Igor may pass very close to Newfoundland, Canada, but it is too early too assess the likelihood of this happening.

JuliaHurricane Julia put on a remarkable and unexpected burst of intensification this morning to become the season's fourth Category 4 storm. Julia's 135 mph winds make it the strongest hurricane on record so far east; the previous record was held by the eighth storm of 1926 which was only a 120 mph Category 3 hurricane at Julia's current longitude. Julia's intensification was a surprise, since SSTs in the region are about 27.5°C, which is just 1°C above the threshold needed to sustain a Category 1 hurricane. Julia is headed northwest, out to sea, and it is unlikely that this storm will trouble any land areas. SSTs will steadily cool to 26.5°C today, and further intensification today is unlikely. Shear will be moderate, 10 - 20 knots, over Julia during the next two days, then rise sharply to 30 knots 3 - 5 days from now, as Julia moves within 1000 miles of Igor and begins to experience strong northwesterly winds from her big brother's upper level outflow. This should substantially weaken Julia.

Elsewhere in the tropicsThe GFS and ECMWF models develop a new tropical depression a few hundred miles off the coast of Africa 3 - 6 days from now. The GFS also develops a tropical depression in the eastern Caribbean 6 - 7 days from now.

Portlight's 2-year anniversary On September 14, 2008, the devastation wrought by Hurricane Ike on Texas and Louisiana moved members of the wunderground community to put into action their own impromptu relief effort. From this humble beginning has grown a disaster-relief charity I have been proud to support--Portlight.org. We've been blessed this hurricane season with relatively few landfalling storms, so Portlight's new disaster relief trailer (Figure 4), financed with a $21,500 grant from the Christopher and Dana Reeve Foundation, has yet to be deployed. With five weeks of peak hurricane season still to come, the new trailer may yet get a call to action. The mobile kitchen in the trailer will be able to feed several hundred people per day, and the trailer is equipped with portable ramps to help with shelter accessibility, as well as durable medical equipment to facilitate mobility and independence for survivors. The trailer is mobile, and Portlight is willing to load it up and fly it to Bermuda, if Igor ends up making a mess there!

The lack of landfalling storms has allowed Portlight to continue to concentrate their efforts on Haiti, where their assistance has been a tremendous boost for those most in need, the disabled. Portlight is working on constructing steel shelters out of shipping containers for homeless Haitians, as detailed in the Haitian Relief Recap blog post. Please visit the Portlight.org web site or the Portlight blog to learn more and donate. A few other items of note:

Portlight has been able to facilitate providing assistance to people with disabilities in Pakistan, where the worst natural disaster in their history has left 4 million homeless. While not directly involved in delivering relief, Portlight has been able to connect local Disabled People's Organizations with important sources of food, water, filtration systems, and medical equipment.

ABC News4 in Charleston broadcast a story about the Portlight relief trailer, and Portlight has also been featured on the Pacifica Radio Network.

Portlight launched a quarterly newsletter, The Portlight View, which can be seen on the newly redesigned website.

Figure 4. The new Portlight disaster relief trailer, funded by their $21,500 grant from the Christopher and Dana Reeve foundation.

Most intense hurricane day ever recorded 2 cat 4s at once Good news both out at sea. Bad news. Pattern favors hits US coast Sept 25-Oct15. Remember, this is all nature working out imbalance.. last part that is left, Caribbean, east/central gulf,and off S atlantic coast. I want you to keep in mind the post I had a few days before all this started.. on hearing the parade before seeing the band. The theory on US hits now is not hocus pocus magic, it is likely because of the physical realities of the northern hemispheric weather pattern and how this should evolve. The rapid development of the storms out at seas invites rapid recurvature. You have to understand, later in the season that becomes less likely, so the later season correction to this imbalance has to occur farther west. It is also part of the reason.. that imbalance, with a focus on upward motion in the gulf, w caribbean and southwest atlantic may be a reason for seasons like this to get out of the box quickly in the winter, before the correction is completed, in which case the winter gets warm. in the very areas that had it worst last year. Classic examples were winters of 1933-34 05-06 and perhaps you will be able to see it coming up. Again, I hear the band before I see it on that matter too. For the cynics out there on this season, and how the atmosphere is driving home its points in correcting the obvious imbalance, the things laid out here are the product of alot of work over the years, and there is the is I can be wrong. It is not that much different from what Frederick Douglas said on the matter of work "People might not get all they work for in this world, but they must certainly work for all they get." . I would rather be wrong looking at all the facts.. than just throw stones from the sidelines and not even give consideration to some theories that people that came before me started to develop. Until it is a done fact, the impacts on the US coast have to fill in to make sure the forecast and the ideas laid out from February are beyond the trivial criticisms that get hurled ones way. I have this "tone", and yes I am defensive, not only because of some of the comments I hear about the motivation behind forecast ideas I lay out for the public to see well in advance of them happening, but because they also are attacks on people and ideas that came before me. It is like that in everything today though in history as well as science. It is as if the very ideas that got us where we are in many things, are simply discarded. And that doesnt sit well with me. So when I see two cat 4s going at once in a season that 3 weeks ago was being scoffed at, and the ace index in the atlantic going through the roof, I will remind folks of some of the things that were being said in other circles.

It is that kind of close mindedness that I am seeing today out there...for instance, the lack of tolerance of AGW positions by a new generation of virtual meteorologists and climatologists, that is most disturbing. Guys like Bill Gray should not be getting dragged through the mud because of their stance on issues they have been looking at long before the Johnny come lately planet savers appeared on the scene.

The hurricanes are part of the correction going on, no more, no less, and part of the reason they are focused and strong in the atlantic has to do with massive pacific cooling that is shutting that area of the world down, and in the longer term, will cause global temps to fall back for next year to levels much like the late 90s.. which by the way should tell you something about cause and effect in the bigger picture

You know what amazes me. Very few things are done without the basics, or without a foundation of truth that cant be denied based on the facts of the past. . No one aces calculus without knowing how to add and subtract first, but would you laugh at the methods that teach those basic things. And the years you can go back and see the similarities are all showing up now, because there is nothing new under the sun, unless of course you never bothered to do the work to look

I have a bad feeling by looking at the trough setup later this month and into October that the eastern Gulf is in for some serious trouble. I would really watch the models the next few days to see if what the GFS is hinting at will come true.

In all seriousness,Dookie, what Jeff says is right. We in FL need to be aware of and watch the Carib. conditions in the next few weeks. I have seen storms form from what appears to be almost nothing so I don't let my guard down until the end of Nov.

Thanks Levi32. This weekend I read a paper with photos of the Oct. 1910 and 1911 Hurricanes (or was it 1909-1910?) which was called a repeater. Quite a bit of damage was done. Neat photos. If you go to www.explorekeywesthistory.com it is a website. The paper is #31 of 2010 and I am not sure how much it costs, but it is full of info. I will try to pick up another one so I get the dates and pressure readings correct. I just don't want a repeater of Wilma. Don't say the "W" word.:)

Thats a bold statement saying only one or two more storms... Especially with models hinting at a couple storms in the next 2 weeks.

I agree. I think 16-18 total storms look to be where we will end up by season's end. We will probably have two more systems form in the next couple of weeks, and going into October through the remainder of the season, I think we will see at least 4-5 more tropical cyclones develop in the SW Atlantic basin, Caribbean Sea and GOM.

I foresee an active late season as much of the Caribbean and GOM has so much warm water that hasn't been stirred up much to this point this season and expect increased instability likely going into the autumn months in these areas. The pattern will shift from what we have been seeing for such a prolonged period this summer in the tropics, and like Dr. Masters pointed out in his Hurricane Haven program yesterday, this season is very reminiscent of 1995. That year was very much like this one, with major hurricanes in the Atlantic curving out to sea away from the CONUS and several storms making landfalls in Mexico. Then we had Opal, a major hurricane, effecting the FL pandhandle in Oct.'95.

Lots of hurricane season still left folks, and I anticipate a busy late September-October period ahead.

"COLORADO STATE UNIVERSITY FORECAST OF ATLANTIC HURRICANE ACTIVITY FROM SEPTEMBER 15 – SEPTEMBER 28, 2010

We expect that the next two weeks will be characterized by above-average amounts of activity (greater than 130 percent of climatology.) These new two-week forecasts have replaced the monthly forecasts that we have been issuing in recent years.(as of 15 September 2010)

By Philip J. Klotzbach1 and William M. Gray2"

Does this imply that their monthly forecast wasn't worth a dime so they cut it to two weeks so that they may get it a little closer to right?

"COLORADO STATE UNIVERSITY FORECAST OF ATLANTIC HURRICANE ACTIVITY FROM SEPTEMBER 15 – SEPTEMBER 28, 2010

We expect that the next two weeks will be characterized by above-average amounts of activity (greater than 130 percent of climatology.) These new two-week forecasts have replaced the monthly forecasts that we have been issuing in recent years.(as of 15 September 2010)